Ted is just trying to get through fifth grade, but his younger sister's imaginary friend starts making that difficult. It was bad enough when Vicki pretended "Marella" was sitting in chairs and talking to her, but then she started sleeping with a hammer under her bed to protect against another imaginary friend. Then Ted himself gets attacked by an unseen force, and he begins to suspect that they aren't Vicki's imaginary friends...they're ghosts.

Spooky but mostly sad, and most of the scares are because of a misunderstanding. There's a useful historical tie-in that could help teach kids about slavery and the Underground Railroad. Meant for a young YA audience.